Ross Detwiler hasn’t pitched in a game since July 3, and it appears unlikely that he’ll be back on a mound in a big league game again the rest of this season.

Detwiler has been out more than seven weeks with a herniated disc in his back, and while the left-hander was back out at Nationals Park running with resistance bands around his waist and doing drills this afternoon, manager Davey Johnson said that Detwiler probably won’t have enough time to work back up to the majors before the season ends.

“He’s been out so long,” Johnson said. “But it’d be nice to see him throwing at full speed before the end of the year. Whether or not that means we take a chance on (him) pitching up here, I don’t know. That’s going to be strictly from the doctors.”

Johnson said that Detwiler has been playing catch, and the Nationals are waiting on clearance from doctors before Detwiler gets back up on a mound. But even after he does, Detwiler will need to go through a lengthy process of building up arm strength and getting his pitch count stretched out. With just 32 games left on the schedule, that would seem to make it tough for him to return in time this season.

Still, the Nats want to get Detwiler back throwing at full speed again, if for no other reason than so they can make sure that the 27-year-old is healthy and won’t need offseason surgery or any other procedures to correct the back issue.

“I think the concern is to accelerate it enough so that he’s throwing and make sure that he doesn’t need any further treatment,” Johnson said. “That’s the key. That’s the only reason to accelerate him coming back to pitching again, to see if everything’s going to be fine going forward.”

Johnson said that Bryce Harper had an X-ray on his left foot after fouling a ball off the foot Sunday in Kansas City, but the results came back negative. Harper finished Sunday’s game by notching two hits including a home run, and is in the lineup tonight.

Jayson Werth battled an infection in his right foot out in Kansas City, but like Harper, he’s in the lineup for tonight’s series opener against the Marlins. Werth will be examined by team medical director Wiemi Douoguih, but Johnson got good reports on Werth today from the Nats training staff.

“There’s no inflammation in the foot,” Johnson said. “It looks a lot better. It looks 100 percent better than it did a couple days ago.”

The Nationals have not conceded this season just yet, especially not with how much better they’ve played the last couple of weeks, but Johnson also is taking a bigger-picture approach when he thinks about how he’ll manage the final 32 games of the season.

“Obviously, some of the young players, like a (Anthony) Rendon, Harper, (Tanner) Roark, are going to get every minute of playing time I can give ‘em,” Johnson said. “Same way with (Wilson) Ramos, who has missed big portions of the last couple years. Trying to get the bullpen a little more settled. Those kind of things going forward. I still think we’re in a pennant drive, not a salary drive. We’re definitely not rebuilding. The talent’s here. We’re starting to perform at the level we expected to start the season at here, lately. But every game’s a big game. Let’s win those games.

“Now’s the time. I still think we need close to 90 games (to make the playoffs). So every game, we need to play well, we need to pitch well. Pitching staff had some hiccups on this road trip. But by and large, we survived it. But going forward, we need to be real consistent going forward.”